In an environment where there mixedly exist access points connected with a wired network and access points not connected with the wired network, a mesh network has been known as a system that sequentially forwards frames received from a terminal between the access points. In the mesh network, forwarding among the access points is carried out in a time-staggered manner so that a time to be taken until the forwarding to the access point is made depends on the number of hops from the access point connected with the wired network.
In order that the access point as a relay station simultaneously performs receiving of frames from another access point and transmitting of frames to a terminal, a scheme has been proposed that both a 2.4 GHz band and a 5 GHz band are used. This scheme needs to use two bands. There is no proposal regarding how achieve forwarding in a case where the forwarding is made via more relay stations.